1. Field of the Invention
The present invention relates to a video processing apparatus and method. More particularly, the present invention relates to a video processing apparatus and method for preventing an artifact from appearing at a vertical edge of an image when de-interlacing a standard definition (SD)-level video signal into a high definition (HD)-level video signal.
2. Description of the Related Art
Two different scanning methods are available to render an image—interlaced scanning and progressive scanning or non-interlaced scanning. Interlaced scanning is mainly used for general TV, and it divides a single image frame into two fields and then alternately displays the two fields, thereby displaying one picture. The two fields are called ‘top’ and ‘bottom’ fields, ‘upper’ and ‘lower’ fields, or ‘odd’ and ‘even’ fields.
Progressive scanning is mainly used for computer monitors or digital TV, and it displays the entire picture frame by frame as if a film is projected onto a screen.
A de-interlacer converts an interlaced video signal into a progressive video signal. Therefore, a progressive display device for processing a progressive video signal requires a de-interlacer in order to process an interlaced video signal.
For example, if a viewer wishes to view an SD-level video signal, for example, a 480i signal, through an HD-level display device, such as a 1080p panel, two times de-interlacing operations are required to up-convert the SD-level 480i video signal into the HD-level 1080p video signal.
The above-described signal processing process will be described in detail below.
FIG. 1 is a flowchart illustrating a conventional signal processing method for displaying an SD-level video signal on an HD-level display device.
Referring to FIG. 1, a first de-interlacer de-interlaces an incoming 480i signal into a 480p signal at operation S10. The first de-interlacing applies adaptive de-interlacing that is realized by temporal-spatial interpolation.
Next, the 480p signal is up-converted into a 1080i signal and the 1080i signal is output at operation S20. The operations S10 and S20 are performed on a single chip.
Next, a second de-interlacer de-interlaces the 1080i signal into a 1080p signal at operation S30. The second de-interlacing also applies adaptive de-interlacing that is realized by temporal-spatial interpolation.
However, the two times de-interlacing operations for converting the SD-level video signal 480i into the HD-level video signal 1080p result in an artifact appearing at the vertical edge of an image. This distortion is especially prevalent around horizontal images such as eyes or cross stripe clothing. The artifact appears on the screen as a horizontal dot line.